G & R Technology Inc. was  founded in New Jersey, USA in 1992. It subsequently moved to California USA in 2002.  G & R Technology Inc. has been designing and building high quality and reliable portable hardness testers for more than 15 years.

In 1994, the HT series handheld testers debuted in the North American market as the smallest and most precise Leeb testers in the world.  There are currently (as of 2006) more than 5000 units of these brand name testers in use worldwide.

Recently, we have updated the HT series hardness testers to be more precise and easier to use as well as having longer battery lives and lifetimes.

In 2006, the U.S. patented RH-150 Rockwell Tester debuted. This convenient portable tester is currently the most precise in the world. It is one of the few portable Rockwell testers that actually measures in the Rockwell scale instead of subsequent conversion to the Rockwell scale. This reliable and versatile tester is suitable for all kinds of Rockwell high precision testing.